Tourette Syndrome

Motor and phonic tics with childhood onset

Cause

• Likely meso-limbic circuit issue - leading to disinhibition

• Structural, functional, metabolic changes

  • Structure = Reduced caudate volume

  • PET shows basal ganglia glucose uptake changes

  • Insula plays role in premonitory urges

  • ? GAS contrbuting but no evidence PANDAS contributes

Genetics

• No gene identified

Epidemiology

• 1 in 200

• M>F = 4:1

• Prenatal smoking = more likely

Features

• Motor tics

  • Simple = Blink, grimace, shrug, head jerk

  • Complex = Coord moves, gait, kick, jump, scratch

  • Dystonic = Oculogyric, sustain mouth opening, torticollis, body posture

  • Force neck tics rarely cause injury

• Phonic tics

  • Simple = Grunt, bark, moaning, throat clearing, sniff, holler

  • Complex = Coprolalia (obscene words), echolalia (repetition of words), and palilalia (repetition of a phrase or word with increasing rapidity)

Character

• Premonitory sensation, relived by execution of the tic

• Precipitation factors

• Temporary suppressibility

• Variable severity

• Waxing and waning

• Evolution over time

Onset

• Typical onset age 2 to 15 - average 6 years

• 96% manifest by age 11

• Tic severity peaks age 10 to 12

• Improvement in adolescence and adulthood

• 1/3 resolve completely, 1/3 improve, 1/3 continue

• Risk of moderate to severe tics = 20 to 25%

• Risk factor for moderate to severe = OCD, ADHD, family history of neuropsychiatric disorders

Comorbidities

• ADHD in 30 to 60%

  • Symptoms emerge 2 to 3 years after onset of tics

• OCD in 10 to 50%

  • Symptoms emerge a few years after onset of tics

  • More severe over time

  • Repetitive counting, arranging, hoarding, touching, tapping, rubbing, and error checking

• Learning disorder in 23%

• ODD in 15%

• Self injury behaviour in 17%

• No comorbidities in 12%

Evaluation

• Neuro exam usually normal

• Imaging usually normal

Differential

• Transient tics of childhood in 25% of kids

Education

• Tourette Syndrome Association Australia

Algorithm

Management

• Mild

  • Education, Supportive care, Watch

• Debilitating

  • Habit reversal training

    • Moderate effects

  • Cognitive Behavioural Intervention for Tics

  • Medication

Medication

Alpha agonists

• Guanfacine

• Clonidine

  • 50mcg oral daily

  • Can titrate up to 300mcg in up to 4 divided doses (3 to 5mcg/kg total daily)

Antidopaminergic drugs

• Haloperidol

• Pimozide

• Aripiprazole

VMAT2

• Tetrabenazine

Topirimate

Botox